tidal wave

Meanings

1. A large and sudden rise and fall in the tide.
2. A large, sudden, and disastrous wave of water caused by a tremendous disturbance in the ocean; a tsunami. (See Usage notes below.)
3. A large, sudden inundation of water from the storm surge, or waves of that surge; a sudden surge of river water.
4. A sudden and powerful surge.
5. A crest of ocean water; a wave.
6. A crest of ocean water resulting from tidal forces.